Advanced packaging solder paste

Abstract

Electronic devices are becoming smaller in size and more chip functions are being integrated into even smaller package systems. The market is also increasingly demanding fine powders for soldering processes. But the continuing trend towards compact size and 3D integrated modules is further increasing the complexity of packaging technology. As the size of electronic devices decreases, the size of the solder powder used in the soldering process also needs to be smaller. However, this reduction in solder powder size leads to a significant increase in overall surface area per unit volume. This makes the solder paste easily oxidised and the performance shown during the soldering process can be significantly reduced. The objective of this project is to investigate how to develop a high-performance solder paste using finer powders. This was done by gaining an in-depth understanding of the principles of Surface Mount Technology (SMT), the role of each component in the solder paste, the rheology performance of the paste and the factors that affect the performance of the paste. Each experiment was carefully designed to ensure safety. After conducting numerous experiments, it has been proven that a high-performance solder paste can be produced with finer powders. This requires consideration of compatibility of the flux and solder powder, the viscosity and corrosiveness of the flux, the melting temperature and stability of the flux, and the weight ratio of the solder powder to the flux to develop a high-performance solder paste.